Japanese Patent Application Publication. No. 2012-409419 discloses a technique of bonding a wire made of copper on an electrode pad made of aluminum. The wire is harder than the electrode pad, and hence at bonding, the electrode pad is crushed by the wire, and a material that constitutes the electrode pad is pushed out from below the wire to a periphery of the electrode pad. Consequently, the electrode pad projects around a bonded portion. This phenomenon is generally called aluminum splash. When aluminum splash occurs, downsizing of an electrode pad becomes difficult. The technique in Japanese Patent Application Publication No. 2012-409419 suppresses aluminum splash by providing an interlayer film partially below the electrode pad.